Abstract: In a communication system, an eNB and a UE transmit and receive a UE monitoring message for confirming the state of the UE in a predetermined UE monitoring period. For example, in UE monitoring periods, a UE monitoring procedure is performed, so that the UE transmits the UE monitoring message to the eNB. Upon receipt of the UE monitoring message, the eNB transmits delivery confirmation information to the UE. The UE monitoring period is set as, for example, a period shorter than a TAU period. This allows the UE monitoring process to confirm the state of the UE even if the TAU period is lengthened. The eNB may transmit the UE monitoring message to the UE.

Abstract: A communication system of the present invention includes a user equipment (UE), and a plurality of cells that perform communication with the UE. The plurality of cells include a macro cell having a relatively-wide-range coverage, and a plurality of small cells having a relatively-narrow-range coverage. The plurality of small cells are connected to a concentrator. The concentrator selects the small cell to which the UE is to be connected, from among a plurality of small cells, based on the flow of at least either one of the received data that each small cell receives from the UE and the transmission data that each small cell transmits to an MME and an S-GW.

Abstract: A cell2 configured by only a DL CC2 being a resource for downlink is configured. The cell2 does not include a resource for uplink, that is, a UL CC to be associated with the DL CC2 by a DL/UL link. The link information indicating the above is notified a communication terminal device by a base station device using the DL CC2. A DL CC1 and a UL CC1 constitute a cell1. The downlink communication from the base station device to the communication terminal device is performed using the cell1 and the cell2, and the uplink communication from the communication terminal device to the base station device is performed using the cell1.

Abstract: The present invention relates to a mobile communication system having a coordinated communication mode in which radio communication is performed between a user equipment and a plurality of base stations in a coordinated manner and an uncoordinated communication mode in which radio communication is performed between a user equipment and a base station without coordinating with another base station, in which radio communication is performed by selectively using any of the coordinated communication mode and the uncoordinated communication mode.

Abstract: A mobile communication system includes a plurality of eNBs that perform radio communication with an UE and an MCE that controls the eNBs. The MCE indicates an MBSFN subframe (MCE) serving as radio resources that transmit a reference signal for power measurement to the UE less frequently than normal to the eNB, the eNB, in addition to the MBSFN subframe (MCE) indicated by the MCE, designates the MBSFN subframe (eNB) serving as the radio resources that transmit a reference signal to the UE less frequently than normal, and in the MBSFN subframe (MCE) and the MBSFN subframe (eNB) the reference signal is transmitted to the UE. In this manner, the reference signal for measuring a power can be transmitted less frequently than normal, and a power consumption of the infrastructure can be reduced.

Abstract: The present invention has an object to provide a communication system capable of minimizing effects due to a delay among a plurality of base station devices as much as possible in scheduling for communication with a terminal device in cooperation among the plurality of base station devices. Cells1 to 3 can each perform scheduling without using information for scheduling notified from one or a plurality of cells among pieces of information for scheduling notified from other cells. For example, in a case where an interface between the cell1 and cell3 has a large delay amount, the cell1 performs scheduling without using information S13 notified to the cell1 by the cell3, and the cell3 performs scheduling without using information S11 notified to the cell3 by the cell1.

Abstract: A mobile communication system includes a CSG cell which is accessible by a CSG member, a hybrid cell which is the CSG cell where a non-CSG member is also allowed access at the same time, and a mobile terminal which is subscribed as the CSG member and connected to the CSG cell or the hybrid cell as the CSG member. Even in a case in which a subscription time period has expired, the mobile communication system enables the mobile terminal to continue the connection. When the subscription time period for the CSG member expires, in case of the mobile terminal's connection to the CSG cell, the CSG cell initiates a handover, in case of the mobile terminal's connection to the hybrid cell, the hybrid cell changes treatment for the mobile terminal from treating the mobile terminal as the CSG member to treating the mobile terminal as the non-CSG member.

Abstract: A data communication method implemented by a communication system including transmitting data by a base station using an OFDM (Orthogonal Frequency Division Multiplexing) method as a downlink access method, transmitting to the base station, by a mobile terminal, a response signal in accordance with a result of reception of the data transmitted from the base station, transmitting to the base station, by the mobile terminal, a scheduling request signal to make a request for allocation of radio resources before transmitting data to the base station, and transmitting the response signal to the base station, a scheduling request signal to the base station, and a control process of, when a transmission timing of the response signal transmission process coincides with that of the scheduling request signal transmission process, allowing a radio resource for transmission of the scheduling request signal to be shared with transmission of the response signal.

Abstract: A mobile communication system capable of easily notifying the interference-related information and avoiding interference in a situation in which a macro cell and local nodes are deployed to coexist. In the system, a macro cell (eNB) notifies, via user equipments (UEs) present in a coverage, HeNBs present in the coverage of the interference-related information related to the interference to a physical resource to be used, for example, a high interference indication (HII) and an overload indicator (OI).

Abstract: A communication system includes a user equipment (UE), and a plurality of cells that perform communication with the UE. The plurality of cells include a macro cell having a relatively-wide-range coverage, and a plurality of small cells having a relatively-narrow-range coverage. The plurality of small cells are connected to a concentrator. The concentrator selects the small cell to which the UE is to be connected, from among a plurality of small cells, based on the flow of at least either one of the received data that each small cell receives from the UE and the transmission data that each small cell transmits to an MME and an S-GW.

Abstract: The present invention relates to a mobile communication system having a coordinated communication mode in which radio communication is performed between a user equipment and a plurality of base stations in a coordinated manner and an uncoordinated communication mode in which radio communication is performed between a user equipment and a base station without coordinating with another base station, in which radio communication is performed by selectively using any of the coordinated communication mode and the uncoordinated communication mode.

Abstract: In a communication system of the present invention, a HeNB measures interference in Step ST41 in an energy saving mode. When judging to have detected the interference by a UE during communication with an eNB in Step ST42, the HeNB cancels the energy saving mode and moves to a normal mode in Step ST43 and starts issuing a pilot signal in Step ST44. When the UE judges to have detected the pilot signal in Step ST23 and reports the judgment results to the eNB in Step ST24, in Steps ST25 to ST32, a handover process from the eNB to the HeNB is performed for the UE.

Abstract: A cell2 configured by only a DL CC2 being a resource for downlink is configured. The cell2 does not include a resource for uplink, that is, a UL CC to be associated with the DL CC2 by a DL/UL link. The link information indicating the above is notified a communication terminal device by a base station device using the DL CC2. A DL CC1 and a UL CC1 constitute a cell1. The downlink communication from the base station device to the communication terminal device is performed using the cell1 and the cell2, and the uplink communication from the communication terminal device to the base station device is performed using the cell1.

Abstract: User equipment includes an antenna, a controller, a transmitter, and a receiver. The transmitter sends a first radio frequency signal for communication with a primary cell to the antenna according to a first timing advance set by the controller, and sends a second radio frequency signal for communication with a secondary cell to the antenna according to a second timing advance set by the controller. The receiver sends received data to the controller including information regarding at least one of the first timing advance and the second timing advance. The first timing advance indicating a first uplink transmission timing alignment value and the second timing advance indicating a second uplink transmission timing alignment value.

Abstract: A mobile communication system capable of easily notifying the interference-related information and avoiding interference in a situation in which a macro cell and local nodes are deployed to coexist. In the system, a macro cell (eNB) notifies, via user equipments (UEs) present in a coverage, HeNBs present in the coverage of the interference-related information related to the interference to a physical resource to be used, for example, a high interference indication (HII) and an overload indicator (OI).

Abstract: A communication system includes a base station configuring an energy saving cell (ES cell) and a base station configuring a compensation cell (Comp cell). The ES cell is switchable between a switch-on state and a switch-off state. The Comp cell compensates for the coverage of the ES cell when the ES cell is in the switch-off state. Before the Comp cell starts compensating for the coverage, for example, before the ES cell decides to switch itself off in Step ST2101, in Step ST2201 for example, the base station configuring the ES cell notifies the UE being connected with the ES cell of the information about a Comp cell, for example, a Comp cell list.

Abstract: In a communication system of the present invention, a HeNB measures interference in Step ST41 in an energy saving mode. When judging to have detected the interference by a UE during communication with an eNB in Step ST42, the HeNB cancels the energy saving mode and moves to a normal mode in Step ST43 and starts issuing a pilot signal in Step ST44. When the UE judges to have detected the pilot signal in Step ST23 and reports the judgment results to the eNB in Step ST24, in Steps ST25 to ST32, a handover process from the eNB to the HeNB is performed for the UE.

Abstract: A cell2 configured by only a DL CC2 being a resource for downlink is configured. The cell2 does not include a resource for uplink, that is, a UL CC to be associated with the DL CC2 by a DL/UL link. The link information indicating the above is notified a communication terminal device by a base station device using the DL CC2. A DL CC1 and a UL CC1 constitute a cell1. The downlink communication from the base station device to the communication terminal device is performed using the cell1 and the cell2, and the uplink communication from the communication terminal device to the base station device is performed using the cell1.

Abstract: A closed subscriber group (CSG) cell is a cell that allows use of subscribers. In order to receive the service by the CSG cell, a CSG-ID is required to be notified to a user equipment, which cannot be obtained in a situation outside the reach of radio waves from a non-CSG cell. In a mobile communication system including base stations respectively provided to a CSG cell and a non-CSG cell in which access is made to the CSG cell with the use of a CSG-ID issued in a case where use of the CSG cell is allowed, the base station provided in the CSG cell refers to the notified identification information of a user equipment and then transmits a tracking area update request from the user equipment to a core network, and the core network determines whether the user equipment is allowed to use the CSG cell and, in the case where the use is allowed, transmits a signal for allowing assignment of radio resources to the user equipment and the CSG-ID. The user equipment accesses the CSG cell with the use of the CSG-ID.

Abstract: A communication system is provided that, if a large number of small cells are installed, is capable of configuring an operation suitable for small cells through simple operation and administration. If a small cell installed in Step ST1401 judges in Step ST1403 that a coverage macro cell, which includes the small cell in the coverage of the coverage macro cell, is present as a result of neighbor cell search in Step ST1402, notifies the coverage macro cell and another neighbor cell of its own capability in Steps ST1404 and 1405. The coverage macro cell selects a configuration parameter suitable for the capability of the small cell in Step ST1406 and notifies the small cell in Step ST1407. The small cell recognizes an operation mode configured by the coverage macro cell from the configuration parameter notified from the coverage macro cell, and then, starts operating in the operation mode.